V2 UPDATE: No longer requires bluetooth controller or keyboard to play. For a better gameplay experience a bluetooth controller is highly recommended.

Impossible Mission, which casts the player in the role of a secret agent infiltrating an enemy stronghold, is widely considered to be one of the best games for the Commodore 64.
A BLUETOOTH CONTROLLER OR KEYBOARD IS REQUIRED TO PLAY THE GAME. PLEASE NOTE: The game runs in an emulator and REQUIRES some configuration of the emulator (See website). The emulator is a faithful recreation of the Commodore 64 home computer.

The situation: for three days the strategic central computers of the great powers have acted up. An unknown person manipulates their programmes; at the end of these programmes is the starting command for the intercontinental rocket. The countdown is on, only 6 hours keep humanity from an atomic inferno. An unknown person? Only professor Elvin, the insane computer expert could crack the top secret start code. Elvin, who entrenches himself in his intangible subterraneous lair, guarded by 90 murderous robots, that until now have hunted down every intruder. No one who has ever set foot on the lift into Elvin's cave labyrinth has returned back alive.

The last hope: Special Agent 4125, the most cunning, toughest and most indiscriminate man, that the secret service can offer. Only ice cold reckoning and a superior physical condition give this unarmed hero a tiny chance to avert disaster in the last minute.

The game: your task is to put a stop to evil Elvin Atombender's game. For this you have to enter his laboratory, protected by a vault somewhere in his underground stronghold. To open the laboratory's door you need a nine letter password, each letter of which Elvin coded into a punchcard, cutting each card in four, painting them in different colors and hiding the resulting pieces everywhere in his base's furniture. So all you have to do is search every object of every room for pieces of the puzzle while surviving the robots, the pits and doctor Elvin's annoying voice, retrieve all 36 pieces, put them together in groups of four, and head for the laboratory, where an unpleasant surprise awaits you.

Setup:
https://www.thawsoe7.co.uk/phoenix-retro-games
https://www.c64-wiki.com/wiki/Impossible_Mission